(1) Field of the Invention
The present invention relates to a waterless urinals and more particularly, to waterless urinal cartridges that include a mechanism to reduce the splashing of fluids exiting the cartridge into a housing or other connected plumbing elements in order to reduce precipitant buildup and to assist in cleaning.
(2) Description of Related Art
Water is a scarce and diminishing resource in many areas of the world. It is widely recognized that more must be done to conserve its usage as populations grow and climates change. Water conserving products are becoming increasingly important not only for quality of human life but also for sanitary and subsistence reasons.
There have been many water conserving measures taken across the world in an effort to deal with limited and diminishing resources. Many municipalities have come up with rationing plans. Others have invested in waste-water recycling treatment and re-use.
There have also been many water conserving products introduced to the market place. These products are becoming more widely used by the industry and home owners as regulations and the rising cost of water usage drive the need for change. Non-flushing urinal designs use far less water than traditional urinals, saving up to 40,000 gallons of water a year from a single urinal. Non-flushing urinals generally comprise three major components: a porcelain urinal, a housing, and a cartridge. The porcelain urinal component is very similar to that of a traditional urinal. The housing replaces a traditional P-trap which normally would connect a urinal to a building's plumbing. Thus, the housing sits in-line between the building's plumbing and the bottom of the urinal where the drain pipe would normally connect. The cartridge fits in the housing and can be removed for servicing and replacement.
There are two types of cartridges for non-flushing urinals: liquid trap style cartridges and mechanical trap style cartridges. The liquid trap style cartridge serves two purposes. First, it acts as a barrier from sewer gasses and odors coming into the restroom. Second, it acts as a filer removing some of the solids that precipitate from human urine (urine is a super saturated liquid). Human urine is an aqueous solution of greater than 95% water, with the remaining constituents, in order of decreasing concentration, urea 9.3 g/L, chloride 1.87 g/L, sodium 1.17 g/L, potassium 0.750 g/L creatinine 0.670 g/L and other dissolved ions, inorganic and organic compounds, according to the NASA Contractor Report No. NASA CR-1802, D. F. Putnam, July 1971. The liquid trap style cartridge works by using two mechanisms. First, urine fills the P-trap of the cartridge forming a barrier against the sewer gasses—just as water does in a traditional P-trapped urinal. Second, a layer of low density fluid, such as oil, is placed in the trap so that it floats on top of the urine. This floating oil forms a barrier keeping unpleasant urine smells from entering the bathroom. As a user urinates into the urinal, fresh urine enters the cartridge, sinks through the floating oil barrier, and presses old urine out of the trap and out through the housing exit tube and into the building's plumbing.
The mechanical trap style non-flushing urinals work in a slightly different manner. All components are similar to the above mentioned liquid trap style of non-flushing urinal except for the cartridge. In this case, the liquid sealant is replaced with some form of a valve that allows urine to go through, while blocking gas and odor from escaping back through the system and into the restroom. An example of this trap is one made by Liquidbreaker and subject of U.S. Pat. No. 7,900,288. In this model two silicone valves are used that rest on plastic seats. When urine flows down on top of the silicon valve at the center of the cartridge, the valve is opened by the weight of the urine. When the urine drips off the valve and into the housing, the valve closes sealing out gasses.
Although there are some significant water-saving benefits from using non-flushing urinals, there are also some drawbacks. One of the most significant is the formation of Struvite in the pipes, housing, and on the mechanical valve components of the mechanical type cartridge. Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NH4MgPO4.6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platey mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid.
While flushing urinals also produce buildup in the pipes, it is found to be more of a hard calcified nature. With non-flushing urinals, it has been found that struvite formation is more common; particularly in areas of slow velocity flows or high splash. The struvite builds up mostly in the leg from the urinal to the building's down pipes in both the mechanical and the liquid trap non-flushing systems unless they are regularly flushed out with water—the building's down pipes receive water from other sources in the building and are thus often rinsed. Struvite also tends to build up in the bottom of the urinal housing, leaving a very unpleasant odor and appearance. This makes changing the cartridge an unpleasant chore for maintenance staff members. When pipes are clogged, they must be snaked out. This can be a difficult and unpleasant process as well.
Struvite also builds up in areas prone to splashing; for example the area underneath the exit of the cartridge. The splashing of urine causes solids to precipitate out of the urine and significant buildup can occur. Additionally, as noted above, struvite tends to build up where urine flow is slow or still. Prior art non-flushing urinal and trap designs suffer from splashing and/or slow flow and as a result, they tend to build up struvite deposits quickly. Increasing velocity of the flow, while minimizing the splash that occurs as the urine transfers from the cartridge or trap to the housing could provide significant improvements over the prior art by diminishing struvite formation.
For the foregoing reasons, it would be desirable to produce a better non-flushing urinal solution; one in which less struvite is formed, especially in the area immediately around the transition from the cartridge or trap mechanism and the housing or plumbing entrance. The present invention overcomes these problems and provides a mechanism to both reduce the splashing of and increase the velocity of urine exiting a non-flush urinal cartridge.